Thaw whipped topping. Mix in jello mix (powder only). Drain as much juice as possible from pineapple. Discard or drink juice. Stir in crushed pineapple. Slowly fold in 1 bag of marshmallows. Smooth out surface when completely mixed. Top with remaining 1/2 bag of marshmallows. Chill until ready to serve. Serves approx. 32 - 1 cup servings.